Acceleration actuated switch



nited States Patent ACCELERATION AKITUATED SWITQH Harold Eugene Ruppel, Fort Wayne, ind, assignor to TIE: Magnavox Company, Fort Wayne, End, a cor-pm in on Application April 29, 1957, Serial No. 655,361

Claims. (Cl. 200--61.45)

This invention relates generally to acceleration responsive control devices, such as switches, and particularly to devices of this type which operate a control means after a predetermined delay period subsequent to the initiation of an accelerated movement of the device.

In the control and operation of accelerated objects, such as rocket-propelled missiles, it is often necessary to utilize a time-delay control device which closes or opens electrical contacts a predetermined time or distance from the initiation of the acceleration. The present invention provides a control device of the type referred to above in which the time delay is determined by the displacement of granular members through an orifice, such displacement occurring as a result of an accelerational force applied to the device.

The principal object of the invention is to provide an acceleration, time integrating device which may include an electrical switch readily adapted to control either single or multiple electric circuits.

A further object is to provide an acceleration responsive time delay control device which responds only to the timed application to the device of an accelerational force of the desired magnitude.

A further object is to provide a device of the type referred to above which, after actuation, may be reset to its original controlling position.

These and other objects will become apparent as the description proceeds with reference to the accompanying drawings in which:

Fig. 1 represents a longitudinal sectional view of an embodiment of the present invention; and

Fig. 2 is a view similar to Fig. 1 but showing the parts in operated position.

Referring initially to Fig. 1, there is shown at 10 a housing, which may be generally cylindrical in shape and preferably formed of brass or similar nonpermeable material. The housing has one end closed by a closure 11, which may take the form of a glass observation window, and the other end of the housing is closed by a cap 12.

The cap 12 and the adjoining portion of the housing accommodate a control means in the form of a switch assembly which includes bayonet-type terminals 13 and 14. These terminals extend through the cap 12 and are received in tubular rivets 16 and 17 which are carried by a plate 18 formed of suitable electrical insulating material. The rivet 17 secures a fixed contact member 19 in overlying relation to the plate 18, and the rivet 16 similarly mounts a resilient blade 21 whose free end forms a movable contact adapted to cooperate with the fixed contact member 19. A switch operating bell crank 22 is pivotally mounted within the housing at 23 and includes a switch lever 26 adapted to engage a switch actuating element or shaft 27. A member 24 formed of magnetically permeable material and carried by the bell crank serves to establish one limit of the pivotal movement of the bell crank about its pivot 23 and further functions as an armature to permit resetting of ice the switch as will subsequently be explained. A depending portion of the bell crank has extending therefrom, a pin 28 which is received within an opening or slot in a block 29 carried by the blade 21 adjacent its free end. With the switch lever in engagement with the shaft 27, as shown in Fig. 1, the contact blade 21 will be held out of engagement with the fixed contact 19. Withdrawal of the shaft 27 from engagement with the switch lever will permit the restoring force existing in the blade 21 to snap the blade into engagement with the fixed contact 19.

A plate 31 separates the portion of the housing accommodating the switch assembly just described from the remaining portion of the housing which accommodates the acceleration responsive time delay device. This portion of the assembly comprises a sleeve 32 nested within the housing and accommodating the plate 31 and a retainer ring 33. By means of the retainer ring and a suitable shoulder formed on the inner surface of the sleeve 32, a cylindrical member 34 and a plate 36, having a flanged central opening therein, are mounted within the sleeve 32, the side walls of the member 34 being spaced from the inner surface of the sleeve. A central wall 37 divides the interior of member 34 into chambers 38 and 39 which have communication through an aperture 41 in the wall 37. Positioned on opposite sides of the wall 37 are pistons 42 and 43 linkedby a rod 44, which extends through aperture 41 and an annular orifice. The pistons 42 and 43 are adapted to move within the cylindrical member 34 and provide movable opposing end-walls for the chambers 38 and 39, respectively. An extension of the rod 44 passes through a central opening in the plate 31 and provides the switch operating shaft 27 which cooperates with the switch lever 26 as previously pointed out.

In its position of Fig. 1, the assembly formed by the pistons 42 and 43 and the rod 44 is in its extreme lefthand position, established by engagement of the piston 42 and the flange 36a formed at the central opening in the plate 36. In this position of the pistons the chamber 38 has a maximum volume and the chamber 39 has a minimum volume. As indicated in Fig. 1, the chamber 38 is substantially filled with granular members 56, relatively small in diameter which may preferably take the form of substantially spherical glass beads averaging approximately .0055 to .0065 inch in diameter, adapted to pass through the annular orifice at 41.

A generally cup-shaped weighted member 51 is accommodated within the sleeve 32 in telescoping relation with the member 34. The end-wall 51a of the weighted member includes a cylindrical member 51b extending within the member 34 and abutting the outer face of the piston 43. A biasing means in the form of a compression spring 52 extends between the inner end of member 51b and an end-plate 53 carried by the sleeve 32. It will be understood that the weighted member is movable with relation to the member 34 but is urged by spring 52 into its position of Fig. 1. The spring 52 thus serves to bias the movable assembly formed by pistons 42 and 43 and the rod 44 into its position of Fig. 1.

In operation, if it is assumed that an accelerating force is imparted to the entire assembly from right to left, as viewed in Fig. l, a reactive force resulting from the acceleration will act on the piston assembly and the weighted member 51, tending to displace the pistons and the member 51 to the right. If the accelerational force is sufficient to compress spring 52, the member 51 will be moved out of engagement with the piston 43 thereby freeing the piston assembly for rightward displacement toward its position of Fig. 2. With the piston assembly released from the biasing force exerted by spring 52, the reactive force exerted on the pistons will cause them to move from their initial position of Fig. 1 toward their the leading chamber 38 through the annular orifice 41 and into the trailing. chamber 39; The movement of the beads through the orifice servesto slow and controlthe movement of the. piston. assembly from itsposition of Fig. l to its position of Fig. 2 and thereby provides a time delay between the initiation of the accelerated motion of the entire assembly shaft 27 from engagement with the swit'clr lever 26, permitting closure of the switch contacts.

Since passage through the orifice determines the time interval between initiation of the acceleration force and actuation of the switch, this time interval may be variedor adjusted by varying the relativesize of the unobstructed portion of the orifice with relation to the size of the beads. The spring 52 and its associated weighted member 51- prevent actuation of the switch by and by accelerat-ional forces of lower magnitude than the desired actuating force.

Resetting of the assemblyto its original position (the position of Fig; 1) can be accomplished by centrifuging the assembly so that an accelerational force a'cts'thereon in the same direction as force. magnet may be placedagainst the outside of the brass housing which attracts the armature 24 thereby pulling the switch lever 26" back into its reset position of Fig. l. A plurality of switch contacts, either normally open or normally closed, or both, may be actuated by the bell crank 22 assembly disclosed herein is merely an example of the type of control means Which may be actuated by' the acceleration responsive portion of the assembly.

Glass window-11 permits visual observation of the operational condition of the assembly through apertures 53a in plate 53.

From the foregoing description of this invention it will be readily apparent that there is provided a simplified mechanism for delaying initiation of a switch in response to accelerative forces. The mechanism is rugged, is impervious to the effects of temperature and humidity and is positive in operation. Rough handling cannot damage the mechanism as would be the case in delicate clock mechanisms such as those shown in-the prior art. Also adequate safety is provided to prevent actuation of the device Whereit' is subjected to relatively heavy blows in handling.

While the invention has been disclosed and described in some detail in the drawing and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and Within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A control device operable in response to accelerative force for a timed interval comprising a housing, a chamber formed within said housing having opposing end-walls aligned in the direction of said accelerated motion, an orifice formed in the trailing end-wall, a mass of granular members within said chamber, the leading end-wall being movable in response to the accelerational force exerted thereon from a first position to a second position to thereby reduce the volume of said chamber from a maximum to a minimum, the time interval required for movement of the leading end-wall from said first to said second position being determined by the rate of displacement of the granular members from the chamher through said orifice, and control means operable by said leading end-Wall.

2. A control device operable in response to accelerative force for a timed interval comprising a housing, a chamber formed within said housing having opposing and the withdrawal of theof the granular members or' beads 56 momentary shock pulses the direction of the actuating- Duringthe centrifuging operation a permanent and it will be understood that the switch' end-walls aligned in the direction of said accelerated motion, an orifice formed in the trailing end-wall, a mass of granular members within said chamber, the leading end-wall being movable in response to the accelerational force exerted thereon from a first position to a second position to thereby reduce the volume of said chamber from a maximum to a minimum, the time interval required for movement of the leading end-wall from said first to said second position being determined by the rate of displacement of the granular members from the chamber through said orifice, biasing means released in response to acceleration and normally urging the leading end-Wall into said first position, and control means operable by said leading end-wall.

3. A control device operable in response to accelerativc motion for a timed interval comprising a housing, a chamber formed Within said housing having opposing endwalls ali ned in the direction of said accelerated motion, an aperture formed in the trailing end-wall, amass of granular members Within said chamber, the leading end wall carrying a member extending through saidaperture and forming an annular orifice, said leading end-wall being. movable in response to the accelerational force exerted thereon from a first position to a second position to therc by reduce the volume of the leadingchamber from amaximum' to a minimum, the time intervalrequired [or movement of the leading end-Wall from said first to said second position being determined by the rateof displacement of the granular members-from the chamber through formed within said housing aligned in the direction of said accelerated motion, an orifice interconnecting said chambers, a mass of chamber, a wall in the leading chamber movable in response to the accelerational force exerted" thereon from a first position to a second position to thereby reduce the volume of the leading chamber from a maximum to a minimum, the time interval required for movement 01."

the movable wall from said first to said second position being determined by the rate of displacement of the granular membersfrom the leading chamber to the trailing'cham'ber throughsaid orifice, and control meansope'rable by said movable Wall.

5'. A control device operable in response to accelerative force for a timed. interval comprisinga housing, chambers formed withi'nsaid housing aligned in the direction of said accelerated motion, an orifice interconnecting said chambers, a mass of granular members within the leading chamber, a wall in the leading chamber movable in response to the accelerational force exerted thereon from a first position to a second position to thereby reduce the volume ofthe leading chamber from a maximum to a minimum, the time interval required for movement of the movable wall from said first to said second position being determined by the rate of displacement of the granular members from the leading chamber to the trailing chamber. through said orifice, biasing means released in responseto acceleration urging said movable wall into said first position, and control means operable by said movable wall.

6. A control device operable in response to acccleratiw said chamber's, a mass of granular memberssubstantially filling the leading chamber, a movable Wall in the leading chamber carrying amember extending through said aperture and obstructing a portion thereof to form an orifice, saidmovable walltbeing adapted to move in response to the accelerational force exerted thereon from granular members within the leading.

a first position to a second position to thereby reduce the volume of the leading chamber from a maximum to a minimum, the time interval required for movement of the movable wall from said first to said second position being determined by the rate of displacement of the granular members from the leading chamber to the trailing chamber through said orifice, releasable biasing means comprising a weight and a spring acting on said member to urge the movable wall into said first position, and control means operable by said movable wall.

7. A control device operable in response to accelerative force for a timed interval comprising a housing, chambers formed within said housing aligned in the direction of said accelerated motion, an aperture interconnecting said chambers, a mass of granular members substantially filling the leading chamber, a piston in each of said chambers forming opposed movable walls therein, a connecting link extending between said pistons and through said aperture obstructing a portion thereof to form an orifice, said pistons being adapted to move in response to the accelerational force exerted thereon from a first position to a second position to thereby reduce the volume of the leading chamber and increase the volume of the trailing chamber, the time interval required for movement of the pistons from said first to said second position being determined by the rate of displacement of the granular members from the leading chamber to the trailing chamber through said orifice, and control means operable by said pistons.

8. A control device operable in response to accelerative force for a timed interval comprising a housing, chambers formed Within said housing aligned in the direction of said accelerated motion, an aperture interconnecting said chambers, a mass of granular members substantially filling the leading chamber, a piston in each of said chambers forming opposed movable walls therein, a piston rod extending between said pistons and through said aperture obstructing a portion thereof, said pistons being adapted to move in response to the accelerational force exerted thereon from a first position to a second position to thereby reduce the volume of the leading chamber and increase the volume of the trailing chamber, the time interval required for movement of the pistons from said first to said second position being determined by the rate of displacement of the granular members from the leading chamber to the trailing chamber through the unobstructed portion of said aperture, releasable biasing means comprising a weight and a spring acting on the piston in the trailing chamber to urge said pistons into said first position, and control means operable upon movement of said pistons into said second position.

9. A control device operable in response to accelerative force for a timed interval comprising a housing, chambers formed within said housing aligned in the direction of said accelerated motion, an orifice interconnecting said chambers, a plurality of granular members substantially filling the leading chamber, a piston in each of said chambers forming opposed movable walls therein, a piston rod extending between said pistons and through said orifice obstructing a portion thereof, said pistons being adapted to move in response to the accelerational force exerted thereon from a first position to a second position to thereby reduce the volume of the leading chamber and increase the volume of the trailing chamber, the time interval required for movement of the pistons from said first to said second position being determined by the rate of displacement of the granular members from the leading chamber to the trailing chamber through the unobstructed portion of said orifice, releasable biasing means comprising a weight and a spring acting on the piston in th trailing chamber to urge said pistons into said first position, the Weight being movable in response to acceleration to remove the biasing force of the spring thereby freeing the pistons for movement into said second position, an element carried by the piston in said leading chamber, and control means operable by said element.

10. A control device operable in response to accelerative force for a timed interval comprising a housing, chambers formed Within said housing aligned in the direction of said accelerated motion, an orifice interconnecting said chambers, a plurality of granular members substantially filling the leading chamber, a piston in each of said chambers forming opposed movable walls therein, a piston rod extending between said pistons and through said orifice obstructing a portion thereof, said pistons being adapted to move in response to the accelerational force exerted thereon from a first position to a second position to thereby reduce the volume of the leading chamber and increase the volume of the trailing chamher, the time interval required for movement of the pistons from their said first to their said second position being determined by the rate of displacement of the granular members from the leading chamber to the trail ing chamber through the unobstructed portion of said orifice, releasable biasing means comprising a weight and a spring acting on the piston in the trailing chamber to urge said pistons into their said first position, the weight being movable in response to acceleration to remove the biasing force of the spring thereby freeing the pistons for movement into their said second position, an element carried by the piston in said leading chamber, and control means comprising switch contacts held in a first controlling position by said element and released by said element for movement to a second controlling position as said pistons move into their said second position. 

